In order to characterize and understand protein function and regulation, proteins must be first separated and then detected. The most common technique for protein separations is gel electrophoresis. Today, 1-D and 2-D polyacrylamide gel electrophoresis (PAGE) setup is commercially available and widely used as a standard technique. Despite its widespread use, however, the PAGE technique has its own limitations, such as requiring a large amount of sample, low reproducibility, breakdown under high electric field, and low dynamic range.
To overcome these limitations of the conventional PAGE technique, a number of new separation platforms have emerged using microfluidic and nanofluidic channels. For example, micro/nanofluidic devices fabricated using conventional semiconductor manufacturing methods potentially use smaller sample amounts, lower electrical field, shorter analysis time, and higher throughput than the PAGE technique. It is desirable to provide an analytical tool and separation medium to control bio-separation, detection, and chemical analysis using nanofluidic devices. Specifically, there is a need to overcome these and other problems of the prior art and to provide systems and methods for controlling a flow and/or a pH value of an electrolyte solution that contains charged species in nanofluidic devices.